Retail shelf supply monitoring system

ABSTRACT

An inventory shelf monitoring system includes a plurality of track systems located on at least one shelf of a retail or warehouse establishment. Each track system includes a sensor and actuator that determines the position of a product pusher. The identity and location of the product pusher, for each track system on the at least one shelf, is sent to a data acquisition and transmitter circuit that assembles, formats, and transmits pusher position data to a central receiver, which receives corresponding data from all shelves employing the system in the retail or warehouse establishment. The data is then transmitted to a central processing unit in a user device that maintains data corresponding to product count, availability, and activity associated with each track unit of each shelf employing the system in the retail or warehouse establishment. Inventory control, the prevention of out-of-stock situations, and the assessment of activity indicative of theft or accident is thus monitored in real time for prompt remedial action.

TECHNICAL FIELD

The disclosure herein relates to monitoring systems for retail shelfsupply. More particularly, the disclosure relates to a modular retailshelf system in which a track of the shelf system is monitored withregard to the presence and removal of product from the track in order toensure security, inventory control, product availability, and the like.Disclosed is a highly integrated modular retail shelf supply monitoringsystem that accommodates the retrieval and analysis of a wide variety ofdata to ensure secure and effective operation of retail establishments.

BACKGROUND

In the operation of any retail establishment, and particularly those inwhich the product for sale is displayed and made readily available uponshelves and within shelf tracks, it is important that restocking ofshelves be effected before or immediately upon exhaustion of the productfrom the shelf. It is further most desirable that theft and otherpilferage be minimized and that safeguards be implemented in thatregard. Indeed, since product turnover equates to profit in most retailestablishments, the ability to constantly monitor on-shelf inventory andproduct availability and capture data indicative of theft or pilferageis paramount. It is further desirable that such systems include theability to alert the retail store management with regard to unusualactivity, out of stock situations, or pilferage so that correctiveaction can be taken as soon as possible. The ability to monitor salesactivities on the basis of day of the week and time of day is recognizedas an important capability in order to enhance sales activities.

It is common in retail establishments that shelves be adjusted, moved,repositioned, or stocked with different products from time to time.Accordingly, the adaptability of retail shelf supply monitoring systemsis key to effective operation. Over any course of time, the productavailable on any particular shelf, or the location of that shelf itself,may vary within the retail establishment. In many instances, thesechanges occur overnight, during periods of low public use, and yet anymonitoring system associated with such a retail establishment must becapable of continuing effective monitoring throughout changeover. Inorder to accommodate shelf changes and rearrangements, the monitoringsystem should typically not be hardwired to the shelves or shelfsystems, but should be modularized. Moreover, communication with a maincontrol system or data acquisition location must also have minimalhardwiring. It should instead be able to accommodate variousarrangements and locations within the retail establishment. In order tomaintain the adaptability, and minimize hard wiring, such systems mustbe, for the most part, battery powered, thus entailing a design thatminimizes power without sacrificing effectiveness and reliability.

There remains a need in the art for a system satisfying the criteriajust presented.

BRIEF SUMMARY

In various aspects described herein, an inventory shelf monitoringsystem comprises at least one track system mounted on an associatedshelf, the track system including a track receiving a pusher that isbiased toward a front end of the track, and a sensor fixed in relationto the track. The system further comprises an actuator attached to thepusher and in communication with the sensor, the sensor emitting a firstoutput signal corresponding to an instantaneous location of the pusherin relation to the track, and a microprocessor coupled to the sensor,wherein the microprocessor controls power to the sensor and measurespusher position. Additionally, the system comprises an electric buslocated adjacent a rear end of the track, wherein the microprocessor iscoupled to the electric bus. Furthermore, the system comprises a dataacquisition and transmitter circuit associated with the associated shelfand in data receiving communication with the sensors of the track systemby receipt of the first output signals, the acquisition and transmittercircuit emitting a second output signal corresponding to the identityand location of the pusher of the at least one track system located onthe associated shelf as a function of measured pusher position. Thesystem additionally includes a receiver receiving the second outputsignals.

In accordance with other aspects described herein, a product inventorymonitoring system comprises a front rail, a back rail spaced from thefront rail, and a plurality of track units coupled to the front rail andthe back rail to form a modular system. Each track unit comprises aspring-loaded pusher that applies force to one or more associatedproduct packages to urge the one or more associated packages toward thefront rail, and a contact pad mounted on a bottom face of the pusher incontact with a sensor strip mounted to the track, the sensor strip beingelectrically coupled to a microprocessor in a sensor circuit, whereinthe microprocessor is in turn coupled to a plurality of buses mounted toone of the front rail and the back rail. Each track unit furthercomprises a power source that supplies a voltage to the one of the frontrail and the back rail, and a data acquisition and transmitter circuitthat is coupled to the track unit and determines a position of thepusher as a function of a voltage difference between the power supplyand a voltage detected across the sensor strip. The system furthercomprises a user device that receives pusher position information andgenerates a report comprising information related to product packagecount in each of the plurality of track units.

According to another aspect described herein, a system that facilitatesmonitoring inventory comprises a data acquisition and transmittercircuit that is interconnected to each of a power bus, a ground bus, anda signal bus. The data acquisition and transmitter circuit comprises adedicated microprocessor chip that receives the data input signals fromthe data bus, from each of a plurality of track units associated withthe data acquisition and transmitter circuit. A pull-up resistor islocated in the track assembly to allow for detection of transmittercable cutting, shorting of the track buses, etc.

The microprocessor formats data received from the plurality of trackunits for transmission, and passes a formatted output signal throughtransmitter circuitry for emission as an RF signal from an antenna. Thesystem further comprises a receiver that receives the transmitted outputsignal and forwards the transmitted output signal through a router to auser device that generates at least one of an inventory report and apilferage report.

DESCRIPTION OF THE DRAWINGS

For a complete understanding of the various aspects, structures andtechniques of the disclosure reference should be made to the followingdetailed description and accompanying drawings wherein:

FIG. 1 is a schematic diagram of the retail or inventory shelf supplymonitoring system made in accordance with a first embodiment of thepresent disclosure;

FIG. 2 is a perspective view of a product inventory monitoring systemaccording to one embodiment of the present disclosure, comprising aplurality of track units that receive product and are disposed between aback rail and a front rail;

FIG. 3 is an enlarged cross sectional view of the system of FIG. 2;

FIG. 4 is an enlarged view of a rear portion of FIG. 3, showing the rearof the track unit coupled to the back rail in greater detail;

FIG. 5 is a perspective view of a product inventory monitoring systemaccording to another embodiment of the present disclosure, including aplurality of track units disposed between a back rail and a front rail;

FIG. 6 is a perspective view of an embodiment of the track unit in whichthe backplate comprises three electrical contacts;

FIG. 7 is an enlarged perspective view of the backplate of the trackunit, according to various aspects described herein;

FIG. 8 is a side-view of the back rail of the system of FIG. 5;

FIG. 9 is a perspective view of a further embodiment of a productinventory monitoring system according to the present disclosure,including a plurality of track units coupled to a back rail and a frontrail;

FIG. 10 is an enlarged perspective view of a track unit of the system ofFIG. 9;

FIG. 11 depicts a monitoring component, and associated electricalcontacts, which are coupled to the buses or conductor strips of thesystem of FIG. 9;

FIG. 12 is a cross sectional view of a track of the system of FIG. 9;

FIG. 13 is an enlarged view of a portion of FIG. 12 illustrating aninterconnection between the track unit and the back rail;

FIG. 14 is a circuit schematic of the pusher sensing circuit employedwith an embodiment of the disclosure;

FIG. 15 is a circuit schematic of the data receiver and transmissioncircuitry associated with the shelf supplying monitoring system;

FIG. 16 is a side elevational illustrative view of another embodiment ofthe disclosure;

FIG. 17 is a side elevational illustrative view of still anotherembodiment of the disclosure;

FIG. 18 is a side elevational illustrative view of still a furtherembodiment of the disclosure;

FIG. 19 is an exploded perspective view of an embodiment of a track unitin which a display device 300 is coupled to the track unit near a frontrail;

FIG. 20 is an illustration of the track unit of FIG. 19, with thedisplay device in its coupled position at the front of the track unit;

FIG. 21 depicts an example of a low stock report that can be generatedusing the system(s) described herein to facilitate efficient and timelyrestocking of shelves in a store;

FIG. 22 illustrates an example of a pilferage report that can begenerated using the system(s) described herein;

FIG. 23 illustrates another embodiment of the shelf system, comprising aplurality of track units that receive product and are disposed between aback rail and a front rail;

FIG. 24 is a cross-sectional view of the back clip housing andassociated components;

FIG. 25 illustrates another embodiment of the shelf system with a backclip cover that covers several components of the system; and

FIG. 26 is a cross-sectional view of the back clip housing andassociated components.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings and more particularly FIG. 1, it can beseen that the retail or other shelf supply monitoring system made inaccordance with the disclosure is designated generally by the numeral10. The system 10 can be mounted on one or more of an array of shelvesin a retail or warehouse establishment, typically comprised of one ormore banks of shelves represented generally by the numeral 12. Suchshelves can hold tracks of various sizes, heights and widths toaccommodate various products. Those skilled in the art will appreciatethat each of the shelves can hold a plurality of tracks, typicallyseparated by dividers, which run perpendicular to the shelf front, withthe product being presented from front to rear in each track. Of course,any desired arrangement and configuration of tracks is conducive toimplementation with the instant monitoring system. Each shelf or bank ofshelves can have associated therewith a circuitry for monitoring thepresence, removal and replenishment of product in each of the varioustracks. In general, this is accomplished by monitoring the position ofthe pusher associated with each track. Of course, not all themerchandise being presented on the bank of shelves 12 may justify beingmonitored. Thus, the system 10 may be present on some shelves and not onothers. Alternatively, some of the tracks on a shelf may be monitoredwhile others are not.

The circuitry associated with a desired track or group of tracks in theretail establishment emits radio frequency (RF) signals 22 carrying dataregarding the activity of each track being monitored. Typically, suchmonitoring occurs at each track at a particular preset interval (everyevery two seconds, every 3 seconds, every 4.2 seconds, etc.).

The data carried by the RF signals 22 is received by a receiver 24which, by wired or RF signals 26, transmits the data to a router 28 thatis in two way communication by connection 30 to a user device 32, whichcan be a laptop or desktop computer, a PDA, a cell phone, or any otherpersonal computing device. The user device 32 can be connected byconnection 34 to a printer 36 for printing of desired reports and thelike. In one embodiment, a user can disable one or more tracks, shelves,or arrays of shelves by inputting a command to the user device (e.g., byclicking on an icon associated with one or more tracks or shelves,etc.). For instance, a user can disable inventory monitoring of one ormore shelves while the shelves are being restocked, in order to mitigateextraneous inventory reporting and the like. Once the shelves arerestocked, the user can re-initiate inventory monitoring thereof byclicking on the same or a different icon.

The router 28 also communicates with wired or RF transmission 38 to asystem of closed circuit televisions (CCTV) 40, positioned throughoutthe retail establishment in relatively concealed fashion for monitoringphysical activities within the retail establishment. The router 28 issimilarly connected by wired or RF transmission 42 to personal digitalassistant (PDA) devices 44, carried by clerical staff and management ofthe retail establishment for receipt of data from the user device 32. Inanother embodiment, the router is communicates using a wired or RFtransmission link 46 to an in-store sound system 48.

With the system of FIG. 1, data regarding the content, removal andreplacement of product within each track of a retail establishment canbe constantly monitored. Data regarding activity pertaining to the samecan be acquired, logged as to date, time, quantity and the like,employed for various activities including inventory control, sending ofout of stock alerts to personnel by means of the PDAs 44, focusingvisual monitoring of areas of interest through the CCTV system 40 bymeans of the router 28 and user device 32, and issuing a wide variety ofreports through the printer 36 to facilitate the implementation ofimproved stocking and management techniques.

A variety of information is provided to a user (e.g., a store manager, aremote corporate manager, etc.) by the system 10. For instance, aproduct count threshold can be selected for each product (e.g.,predetermined or adjusted on the fly), below which an alert is triggeredthat the shelf 12 requires restocking or attention. For instance, iffive packages of a given product fit on a shelf, then the countthreshold can be set to one, so a clerk is alerted to restock the shelfwhen only one package is left thereon.

According to another feature of the system 10, products are time-stampedas they are stocked on the shelves, time-stamped when they are removedby a customer and time-stamped when they are rung up by a cashier.Timestamps can be used for a variety of purposes, including but notlimited to pilferage reports or alerts, end-of day reports, alerts toone or more of the user device 32, CCTV 40, PDA 44 or blackberry,in-store sound system 48, etc. For example, if the shelf system detectsthat an unusually high number of items have been removed from a shelfsince a previous measurement, and no such items have been rung up by acashier for a predetermined time period, then an alert can be sent to amanager indicating that a potential shop lifting event is in progress orhas occurred. To further this example, it may be determined that theaverage time that a customer spends in a given type of store is 15minutes. In this case, the predetermined time period may be set to 15minutes. If a large number of product packages are removed from theshelf 12 and not rung up within 15 minutes, an “inactivity” alert issent to the user device 32 or one of the other means for alerting astore employee (e.g., sound system, CCTV, PDA, etc.). The store employeecan then review video from the CCTV system 44 to identify a customerthat removed the product packages and monitor the customer throughcheckout to ensure that the items are paid for. It will be appreciatedthat the predetermined time may be set to any desired time period, andis not limited to the average time a customer spends in the store.

In another example, the time stamps are employed for periodic reports(e.g., daily, weekly, etc., to provide information about product latencyon the shelves. This information can be used when analyzing productpopularity with customers and determining whether shelf space allocatedfor a given product should be adjusted.

According to another feature of the system 10, a user enters parametersto the user device 32 for product monitoring. For instance, the user canenter a monitoring time period for respective days of the week (e.g., 8am to 8 pm, etc.) to conserve power in the system. Additionally oralternatively, the user can set pusher measurement intervals, pilferageparameters (e.g., removal of N products in X minutes from one or moretracks, lag interval between time stamps for product removal andcheckout, etc.), count thresholds that trigger restocking alerts, etc.Pilferage parameters can include a predetermined threshold number ofproduct packages, a time frame for removal of the threshold number ofpackages, etc., wherein the removal of threshold number of packages canbe monitored across one or more tracks containing a given product orproducts. An alert triggered by any of the foregoing can be timestampedand logged, and can specify the location within the store of thetrack(s) that triggered the alert.

FIG. 2 illustrates a shelf 12 comprising a plurality of track units 60that receive product and are disposed between a back rail 62 and a frontrail 64. The track units s 60 are oriented normal to the rails 62, 64,and comprise a pusher 66 that urges product toward the front rail 64,such that when a consumer removes a product unit, remaining productunits in the track 60 are pushed forward in an orderly fashion andretained between the pusher 66 and the front rail 64. The pusher 66moves between the back rail 62 and the front rail 64 along a pair oftracks 68. In one embodiment, the track unit 60 comprises a spring (notshown) that supplies a retaining force against the rear of the pusher 66to urge the pusher 66 forward upon removal of product.

The shelf 12 further comprises a wireless transceiver 70 that receivesinformation from, and transmits information to, each track unit 60. Forinstance, the transceiver 70 can receive information related to pusherposition at predetermined temporal intervals. Dimensions of the productpackage are stored in and analyzed by a user device, such as the userdevice 32 (FIG. 1), and thus pusher position can be divided by acorresponding package dimension to determine a number of packagesremaining between the pusher 66 and the front rail 64.

The transceiver 70 can additionally receive information from the trackunit 60 and/or from product packages (e.g., from an RFID tag or barcodethereon), and a table lookup can be performed (e.g., by the user device32) to determine product package dimensions or other useful information.

In one example, each track unit 60 includes a processor (not shown) andrelated circuitry that periodically powers up and reads a position ofthe pusher to determine how much product is left in the track unit.Pusher position can be determined as a function of voltage and/orcurrent measured in a sliding potentiometer (not shown) coupled to thepusher and positioned longitudinally between the tracks 68. The intervalbetween measurements can be predetermined or selected, and may be on theorder of seconds, minutes, hours, etc. By intermittently waking andmeasuring pusher position, power is conserved. To further conservepower, no data is transmitted to the transceiver unless a positionchange has been detected between the current position and the positionremembered from the prior wake-up. To further conserve power, thetransceiver need only send measurement information to the user device ifthere is a change in pusher position relative to a previous measurement.In this manner, the system of shelves facilitates inventory tracking fora given product during the time between delivery by a supplier and salesto a customer.

According to other features, a plurality of the track units 60 and/orthe shelves are used for a single product. Alternatively, differenttracks on a single shelf can comprise different products. Stillfurthermore, the “smart” shelves 12 may be employed in a combinationwith “dumb” or regular shelving units. In such cases, the smart shelvesmay be delegated for higher-priced items. Moreover, the tracks 68 arelaterally adjustable along the rails 62, 64 to accommodate productpackages of different widths. The track systems disclosed herein can bemoved throughout a store because they are self-contained units.

Each shelf 12 and each track unit 60 has a unique identity (e.g., anaddress). When stocking the shelves for a first time with a givenproduct, product identity information is stored in the transceiver (andtransmitted on to the user device 32), as is track and shelf identityinformation. For instance, a user scans a barcode on the product toinform the system of the identity of the product being stocked. The userthen scans a barcode located on the track into which the product isbeing loaded. The user device then pairs the product to the track. Thispairing can be employed to perform a table lookup or the like of productdata (e.g., package dimensions, etc.) stored in memory (not shown) inthe user device. Based on the package dimension information, the userdevice can determine a distance that the pusher is expected to travelforward upon removal of a product package by a customer. Additionally, abarcode on the shelf can be scanned to tie the product to the entireshelf, when only one product is being place on the shelf.

FIG. 3 illustrates the track arrangement for various embodiments of thedisclosure. In one embodiment, each of the track units 60 includes thepair of rails 68 receiving the L-shaped pusher 66, which is urged towardthe front wall 64 by means of a coil spring 80 connected to the frontwall 64, with the coil being positioned behind and urging against thepusher 66. Accordingly, the pusher 66 is urged toward the front wall 64in order to secure and retain product therebetween. Those skilled in theart will appreciate that the product is typically in the form ofcontainers which can have a generally rectangular or cylindricalconfiguration. Of course other product configurations are also known.The monitoring system disclosed herein can also be adapted for use withsuch other types of products being sold by the merchant. The pusher 66includes an upwardly extending pusher plate 82, which is substantiallynormal to a baseplate 84. The coil spring 80 is nested therebetween. Asensor strip 90 is interposed along the length of the track unit 60 andbetween the pair of tracks 68. The sensor strip 90 can exhibit variouscharacteristics, depending upon the nature of the embodiment employed,and is adapted for contacting engagement a contact pad 92 located on thebottom of the baseplate 84. The sensor strip 90 may be conductive,resistive, capacitive, inductive, or of any various natures dependentupon the nature of the system employed. In one embodiment, the sensorstrip 90 is a sliding potentiometer, and the position of the contact padrelative to the back rail 62 is determined as a function of a detectedvoltage and/or current in the sensor strip. The rearward portion of thetrack unit 60 coupled to the back rail 62 is marked in FIG. 3 as “DetailA,” which is expanded in FIG. 4.

FIG. 4 illustrates the rear of the track unit 60 coupled to the backrail 62 in greater detail. The track unit 60 includes a back clip 100that fits removably over the back rail 62 and includes a printed circuitboard (PCB) 102 that mates with three spring connectors 104 on a flexcircuit 106 coupled to the back rail 62. The PCB 102 includes a sensorcircuit that is coupled by a microprocessor to buses in the flex circuit106, as described below with regard to FIGS. 14 and 15. The track unitincludes a slider or linear potentiometer 90a that is positioned betweenthe tracks 68. The contact pad 92 (FIG. 3) is in forceful contactingengagement with the potentiometer. The potentiometer 90 a is a resistiveelement of uniform cross-section, where the resistance between thecontact pad 92 and one end terminal 104 is proportional to the distancebetween them. As the contact moves (e.g., due to product removal), thevoltage between the back rail 62 and Accordingly, movement of the pusher66 causes the resistance of the potentiometer 90 a to change in a mannerdirectly analogous to the position of the pusher 66. Thus, the resultingvoltage change is directly analogous to the number of containers ofproduct remaining in the track unit 60. While a spring biased pushersystem is illustrated and discussed herein, it will be appreciated thatthe monitoring system could also be adapted for use with known types ofgravity-based pusher systems as well.

FIG. 5 is a perspective view of the shelf system 12 including aplurality of track units 60 disposed between the back rail 62 and thefront rail 64. A power source 120 is coupled to the back rail 62 andprovides power to the track units 60 for measuring voltage in respectivesensor strips. In one embodiment, the power source is a 3V power source(e.g., using two AA batteries or the like); although it will beappreciated that any suitable power source can be employed in accordancewith the various embodiments and examples described herein.

The front rail 64 includes a base plate 122 and a front wall 124 thatretains product packages in the track unit 60. Similarly, the back rail62 includes a baseplate 126 and a back wall 128, to which the powersource 120 may be mounted. Additionally, each track unit 60 includes adivider 132 that separates product packages in one track unit frompackages in an adjacent track unit. Each track unit further comprises abackplate 130 that couples a sensor strip (not shown) to the powersource 120.

FIG. 6 is a perspective view of an embodiment of the track unit 60 inwhich the backplate 130 comprises three electrical contacts 140. Forexample, a first contact 140 a may be connected to a positive terminalof the power source to receive current therefrom. A second contact 140 bmay be employed to detect digital bus signals. A third contact 140 c maybe connected to ground. In this manner, the position of the pusher 66may be determined by measuring the voltage at contact 140 b. Oneadvantage of providing the contacts on the backplate is to reduce thechance that the contacts will be damaged as product or inventory isremoved from or added to the track unit.

According to an example, as distance increases between the pusher 66 andthe back rail 62, a greater amount of resistive material in thepotentiometer is included in the circuit. As resistance is increased,voltage at contact 140 b decreases, assuming a constant current from thepower source 120. Thus, voltage at contact 140 b correlates to distancebetween the pusher 66 and the back rail 62. Since product packagedimensions are know, including package depth in the direction normal tothe front and back rails, product package count can be determined fromthe voltage measured at contact 140b. A microprocessor (not shown) isconnected between the sensor circuit (not shown) and contacts 140 a, b,and c, as described with regard to FIGS. 14 and 15.

FIG. 7 is a blown-up perspective view of the backplate 130 of the trackunit, according to various aspects described herein. The backplate 130can include the three contacts 140, which extend through the backplate130 to a printed circuit board (PCB) 150 which contains a track controlmicroprocessor or the like, which is coupled to the backplate 130. Inone embodiment, the contacts 140 are vertically oriented.

FIG. 8 is a side-view of the back rail 62 of the shelf monitoring system10. The back rail 62 includes the baseplate 126 and back wall 128 forcoupling one or more track units 60 to the back rail 62. The back wall128 includes a PCB 160 with three conductive strips 162 a, 162 b, 162 cthat carry current to and from track units. The conductive strips 162correspond to the electrical contacts 140 on the backplate 130 of thetrack unit 60. In one embodiment, the conductive strips are verticallyoriented and are spaced from the bottom of the back rail. This geometryis advantageous because it reduces the possibility that the strips willbe soiled during use of the system, such as by dirt or by leakage offluids onto the strips. Also, the location of the strips at the rear endof the track reduces the chance of damage to the strips during use ofthe track to which the monitoring system is attached. The bottom side ofthe baseplate 126 has a plurality of ridges 164 that extend along thelength of the back rail 62 (e.g., into and out of the page), which maybe rubber, plastic, or some other material with a relatively highcoefficient of friction to stabilize the back rail on a shelf in astore.

FIG. 9 illustrates an elevated view of the smart shelf 12, including aplurality of track units coupled to the back rail 62 and the front rail64. The baseplate 122 of the front rail 64 has one or more grooves alongwhich the track units 60 can be laterally adjusted to accommodateproduct packages of different sizes. The grooves also add stability totrack unit position and assist in maintaining a substantiallyperpendicular orientation of the track units 60 relative to the rails.Additionally, the front rail 64 has a plurality of holes 172 into whicha front portion (e.g., a tab or the like) of the track unit 60 isinserted to hold the track unit in place. The back rail 62 optionallyhas similar grooves and holes.

FIG. 10 is a perspective view of an embodiment of the track unit 60. Thebase plate 84 of the pusher 66 includes a pair of slides 180 adapted forlocking sliding engagement with the rails 68 by means of U-shaped endpieces. Between the slides 180 is a contact pad 92, which extendsdownwardly beneath the slides 180, and thus between the rails 68 tocontact a sensor strip 90. For certain embodiments of the presentdisclosure, the contact pad may simply be a pressure pad, while in otherembodiments, the contact pad 66 may include electrical contacts formaking electrical interconnection in manners that will become apparentbelow.

With a general understanding of the structure of the monitoring systemdescribed with regard to the preceding figures, an appreciation ofparticular embodiments thereof can be obtained with further reference tothe figures previously described. In one embodiment of the disclosure,the contact pad 92 of the base plate 84 of the pusher 66 includes amagnet, and the sensor strip 90 comprises an array of magnetic reedswitches and an analog resistor string interconnected to a power source.The magnet on the pusher base 84 actuates reed switches on the sensorstrip 90, which in turn closes the circuit to a specific resistor value.The value of this resistance determines the voltage drop generatedthereacross and, with standard voltage divider techniques, the outputsignal is indicative of the position of the pusher 66 upon the tracks68. In turn, this is indicative of the number of product containersmaintained upon the track.

In another embodiment, which will be discussed in detail later herein,the sensor strip 90 comprises a slider potentiometer, and the contactpad 92 is in forceful contacting engagement with the wiper of thepotentiometer. Accordingly, movement of the pusher 66 causes theresistance of the sensor strip 90 to change in a manner directlyanalogous to the position of the pusher 66. Accordingly, the resultingvoltage change is directly analogous to the number of containers ofproduct remaining upon the track system 60.

According to another embodiment of the disclosure, a magnetic patternmay be imprinted upon the backplate 130, with the pusher 66 including amagnetic read head affixed thereto. With the magnetic pattern having aunique pattern defining a position, or a fixed set of points that may beread along the way, as the pusher 66 moves upon the tracks 68, theoutput of the magnet read head corresponds to the location of the pusher66 upon the track and, consequently, the number of product containersremaining upon the associated track.

In yet another embodiment of the disclosure, a capacitance measurementmay be employed to determine the location of the pusher 66. In such anembodiment, an electrical contact on the base of the contact pad 92 ofthe pusher 66 comprises a first electrode, while the sensor strip 90 maycomprise a series of second electrodes, with the circuit upon thecircuit board determining the capacitance between them. This capacitancevaries as a function of the position of the pusher 66 upon the tracks68.

In still another embodiment of the disclosure, the sensor strip 90 maycomprise a first conductor that is in turn coupled to a secondconductive element, such as an iron core or the like, mounted on thecontact pad 92 or comprising the electrical contact of the pusher 66. Asthe pusher 66 moves along the inductor of the sensor strip 90, thefrequency of an oscillator signal coupled thereto would change in directrelation to the distance of the pusher along the inductive strip.Accordingly, a correlation could then be made with the number ofpackaged products 56 maintained upon the track 68.

As a variation of the foregoing with respect to oscillator frequency,the sensor strip 90 may comprise an inductive coil, with a secondconductive coil being maintained upon the contact pad 92 of the pusher66. Energization of one of the coils will induce a voltage in the othercoil corresponding to the relative position of the one to the other. Inother words, the amount of coupling is directly proportional to theposition of the pusher 66 and, accordingly, the amount of product beingheld by the track system.

In another embodiment of the disclosure, the sensor strip 90 maycomprise a magneto resistive strip, the resistance of which may bevaried by a magnet placed thereover. With a magnet being attached as aportion of the contact pad 92, the resulting resistance of the rod 90may be changed as a function of the position of the pusher 66 and,accordingly, the amount of product upon the shelf.

Another structure and technique for determining the position of thepusher 66 is the use of an encoded printed circuit board. In thisembodiment, an encoded conductive pattern may be printed as a printedcircuit board mounted to the backplate 130, with appropriate wiperscomprising the electrical contacts 140. The conductive pattern and thewipers make a unique contact arrangement corresponding to the positionof pusher 66.

The instant disclosure further contemplates the implementation of straingauges or other such transducers to assess the position of the pusher66. In one such embodiment, a strain gauge may be mounted as part andparcel of the spring 80. As pusher 66 moves along the rails 68 towardthe front wall 64, the force sensed by the strain gauge reduces, thereduction corresponding to the position of the pusher 66 and,accordingly, the amount of product held on the track or assembly.

In yet another embodiment of the disclosure, the sensor strip 90comprises a linear variable differential transformer (LVDT), with thearmature thereof being connected to and driven by the contact pad 92 ofthe pusher 66. Accordingly, the output signal of the LVDT corresponds tothe position of the pusher 66 and the associated volume of product.

In the embodiments just described, the various contacts 140 a, 140 b,140 c and the buses or conductor strips 162 a, 162 b, and 162 c engagewith each other and communicate the resulting data signals to dataacquisition and transceiver 70 as described above. In each of theembodiments, an electronic sensor of sorts may be employed inassociation with the pusher 66 to determine its position and, in turn,the user device 32 assesses the amount of product remaining on the tracksystem 60.

FIG. 11 depicts a monitoring component 190, and associated electricalcontacts 192 a, 192 b, and 192 c, which are coupled to the buses orconductor strips 162 a, 162 b, and 162 c, respectively. The monitoringcomponent can be mounted to the rail assembly at any location such thatit maintains contact with the sensor and communicates with the contactrail assemblies for power and communication. The monitoring component190 includes a printed circuit board with circuitry thereon, which isdescribed in greater detail below with regard to FIGS. 14 and 15.

FIG. 12 illustrates the track unit 60, with a rearward portion thereof,which includes the back rail 62, enclosed in an area labeled “Detail B,”which is enlarged in FIG. 13 and described with regard thereto.

FIG. 13 is an enlarged view of Detail B, showing an interconnectionbetween the track unit 60 and the back rail 62. A baseplate 200 of thetrack unit 60 supports the sensor strip 90 and includes a notch 202 thatcouples with a clip 204. The clip interlocks with the back rail 62 tosecure the track unit 60 to the back rail 62.

With reference now to FIGS. 14 and 15, an appreciation can be obtainedwith regard to the circuitry employed in association with an embodimentof the disclosure employing a membrane potentiometer as the sensor strip90 as presented above and described with regard to the precedingfigures. As shown in FIG. 14, a sensing circuit 210 is provided on eachtrack system, such as the track system 12. Accordingly, the sensingcircuit 210 is associated with a specific track system upon a specificshelf and is further associated with a specific pusher 66. In oneembodiment, the sensor strip 90 is a membrane potentiometer in which theposition of the wiper is determined by the contact pad 92 upon thepusher 66. A microprocessor chip 212 is provided as part and parcel ofthe sensing circuit 210 and is powered by the supply voltage providedthrough a spring loaded contact 140 a, fed by the associated power bus140 a. The supply voltage is also provided as the input voltage to thepotentiometer 90 a by means of the power connector 214. A filtercapacitor 216 is provided in standard fashion to keep the supply voltagestable and to eliminate noise.

The ground provided to the microprocessor chip 212 is provided by meansof a spring loaded contact 140 c, which is selectively interconnected tothe potentiometer connector 218 by means of the microprocessor 212. Theselective interconnection is undertaken in order to prevent power orbattery drain through the potentiometer 90 a. The output of thepotentiometer 90 a is provided to the microprocessor 212 through theconnector 220, which is interconnected to the potentiometer wiper.Accordingly, the microprocessor 212 receives a signal corresponding tothe instantaneous position of the pusher 66 and the amount of productretained thereby.

The microprocessor 212 is bidirectionally interconnected through aspring contact 140 b to the signal bus 140 b. In operation, themicroprocessor 212 is programmed to turn on for a very slight duration,on the order of milliseconds, at predetermined intervals (e.g., 2seconds, 3 seconds, etc.). This duty cycle may be selected to achievethe desired resolution, minimize power drain, and optimize systemintegrity. In any event, when the microprocessor turns on, thepotentiometer ground is interconnected by means of the connector 218 andthe position of the potentiometer wiper is determined by monitoring theconnector 220. If the position of the potentiometer wiper has changedsince the last reading, the microprocessor 212 looks to determinewhether the data bus 140 b is quiescent. When such quiescence is found,an output signal is emitted thereto corresponding to the newinstantaneous position of the potentiometer wiper 220. This information,along with an address signal identifying the specific track system withwhich the microprocessor 212 is associated, is then passed to the dataacquisition and transmitter circuitry 72 uniquely associated with theshelf that houses the track system and associated sensing circuit 210.The microprocessor also monitors the data bus to receive anacknowledgement from the transmitter, and continues to transmit datauntil a valid receipt is received.

As shown in FIG. 15, the data acquisition and transmitter circuitry 230is interconnected to the supply voltage by means of the power bus 140 a,to the ground bus 140 c, and to the signal bus 140 b.

The circuitry 230 prominently includes a dedicated microprocessor chip232 that receives the data input signals from the data bus 140 b, fromeach of the track systems associated with the shelf of the circuit 230.The data is optionally applied through a pull-up resistor 234. Inanother embodiment, the pull-up resistor is positioned in the track unitto permit detection of bus shorts, tampering, etc. It will beappreciated that the data received from the sensor circuit 210 (FIG. 14)associated with the particular track system 12 includes location of thetrack system, as well as the specific location of the pusher 60associated therewith. The track system and/or shelf serial number iscontained in the transmitter microprocessor 232. The microprocessor 232then functions to format the various data received from the tracksystems of the associated shelf. The microprocessor 232 formats thisdata and adds the shelf serial number data for delivery to a transmitterportion of the circuitry 230. Formatting includes a designation as tothe serial number or identity of the shelf, the serial number oridentity of the track system (and associated pusher), the status of thebattery supplying power to the circuitry associated with the shelf, amessaging sequence number to prevent duplication of data, and the like.The formatted output signal is passed through the transmitter circuitry236 for emission as the RF signal 238 from the antenna 240. Thisinformation is then received by the receiver 24, passed through therouter 28 and to the user device 32 of FIG. 1. In one embodiment, thereceiver 24 is a transceiver that communicates bidirectionally with thetransmitter circuitry 236.

In another embodiment, capacitive loading (e.g., one or more filtercapacitors) is employed in conjunction with the circuits describedherein to reduce interference that may arise from ambient sources (e.g.,fluorescent lights, etc.) in the vicinity of the circuitry.

Determining the state of the battery charge is facilitated by means ofthe Zener diode 242 and associated resistor 244, as shown. In standardfashion, the circuitry 230 includes a battery connector 250 and aprogramming connector 260, the latter of which allows reprogramming ofthe microprocessor 232 on site. Additionally a pull-up resistor (notshown) is provided in the track unit added to allow detection of anyshort circuits of the track conductors and/or detection of any breaks inthe connections to the track. If a fault is detected an immediate alarmmessage is sent.

With reference now to FIG. 16, still another embodiment of thedisclosure can be seen as designated generally by the numeral 270. Thetrack system remains substantially the same as the system 12 presentedabove in various embodiments. However, the track system 270 employs awheel 272 as the movement/location sensor associated with the pusher 66.The wheel 272 is operatively connected to the coil spring 80 and rotatesas the spring moves. Alternatively, the wheel 272 may frictionallyengage the track 68 to effect rotational movement. In either event,according to one embodiment, the wheel 272 is encoded such that it emitsa signal corresponding to set fractions of rotation of the wheel 272.These fractions of rotation correlate with linear movement of the pusher66 and, accordingly, the amount of product between the pusher 66 and thefront wall 64. Such encoded wheels are, of course, will known in theart.

Alternatively, the wheel 272 may include a piezoelectric pulsegenerator, the movement of which generates a pulse, again correspondingto linear movement of the pusher 66. In either embodiment, a rotationalmember, producing signals corresponding to an amount of rotation, iscorrelated with the linear movement of the pusher 66 and the volume ofthe product.

With reference now to FIG. 17, yet another embodiment of the presentdisclosure is shown in the form of the track assembly 280. Again, thetrack assembly 280 is similar to the embodiment 12 presented above, butfor the inclusion of a signal emitter 282 fixedly attached to a rearwall of the shelf assembly 280 and in communication with a receiver 284mounted to the backplate 82 of the pusher 66.

According to one embodiment, the transmitter 282 transmits ultrasonicsignals that are received by the receiver 284. The time betweentransmission and reception correlates to the position of the pusher 66and, accordingly, the amount of product remaining. Alternatively, theunit 282 may be a transponder (e.g., an ultrasonic transponder, anoptical or light transponder, etc.) that both sends and receivessignals, and the unit 284 may be simply a reflector, reflecting thesignals back to the transponder 282. In either event, the position ofthe pusher 50 is correlated with the time of travel of the ultrasonicsignals, which in turn correlates to distance.

The track system 280 may also operate as an optical system. In thisembodiment, the unit 282 may comprise a light emitter and an array ofphotocell receivers. The unit 284 can be simply a reflector on the backof the pusher 66. As light is emitted by the emitter/receiver 282, itimpinges upon the reflector 98 and is reflected back to the receiverportion of the unit 282. The particular photocell that is impinged bythe light can be coordinated with the position of the pusher 66 usingtriangulation techniques.

According to still another embodiment of the track system 280, thetransmitter 282 can be of various natures, such as optical, magnetic,radio frequency, acoustic, or the like. The signal emitted would bereceived by the receiver 98 (and/or signal monitoring circuitry) and thesignal strength received would correlate with the position of the pusher66 and, again relate to the amount of product retained by the tracksystem 280.

The system 280 may also function in association with radar rangingtechniques. With the unite 282 being a millimeter wavelength radartransponder, and the unit 284 a reflector (or receiver), the location ofthe pusher 66 can be readily determined within a millimeter as afunction of the time elapsing between emission and reception of theradar signal. Accordingly, the location of the pusher 66 can bedetermined and the amount of product thereby assessed.

With reference now to FIG. 18, another embodiment of the track system ofthe present disclosure can be seen as designated by the numeral 290. Inthis embodiment, a pressure bellows or air spring or air cylinder/pistonarrangement can be employed. This operative structure is designated bythe numeral 292 and includes herein a pressure sensor 294. With thepusher 66 being connected to the pressure bellows or air spring, or tothe air piston received within an air cylinder, the pressure maintainedwithin the unit 292, as sensed by the pressure sensor 294, wouldcorrelate with the position of the pusher 66 and, accordingly, theamount of product retained within the track.

It will be readily appreciated that each of the system described aboveis operative to provide instantaneous information, depending upon theduty cycle of inquiry, as to the location of the pusher 66. Accordingly,the data can not only be correlated with the amount of product remainingon the track, but can also determine, in conjunction with the userdevice 32, when the product was removed, and whether an abnormal amountof product was removed at any given time, indicating the possibility oftheft. In such an instance, the user device 32 could highlight theactivity by means of CCTV TV camera 40 having the track system ofinterest within its view. An alarm (not shown) could also be activatedso that store personnel could take appropriate remedial action.

FIG. 19 illustrates an embodiment of the track unit 60 in which adisplay device 300 is coupled to the track unit 60 near the front rail64. The display device 300 comprises an interface 302 that removablycouples to the track unit 60, and a screen 304 on which productinformation can be displayed. For instance, when a product is coupled tothe track unit (e.g., by scanning barcodes on the track unit and theproduct to be place therein), product information (e.g., price,discounts, sale conditions, etc.) can be received from the user device32 (FIG. 1) and presented to customers via the screen 30. In anotherembodiment, the screen comprises a plurality of differently colored LEDsthat can indicate different conditions to store personnel. For instance,a red LED can indicate an empty track unit; a yellow LED can indicate alow-stock condition, and so on.

FIG. 20 is an illustration of the track unit 60 with the display device300 in its coupled position at the front of the track unit.

FIG. 21 depicts an example of a low stock report 310 that can begenerated using the system(s) described herein to facilitate efficientand timely restocking of shelves in a store. A plurality of products isshown as well as respective product counts, shelf identities, and shelflocations. Where a product count is shown as zero (0), a store employeecan quickly restock the associated shelf because the report indicatesthe location of the shelf and the product that requires restocking.

FIG. 22 illustrates another example of a pilferage report 320 that canbe generated using the system(s) described herein. For instance,high-priced items such as pregnancy tests, which are typically onlypurchased in small numbers, are depicted in the report. A product countdifference of 7 units since a last reading can trigger an alert to astore manager, who can then access the CCTV system 44 to review video ofsection 2 in the store in order to determine whether a theft hasoccurred or is in progress and to identify the potential thief.

Thus it can be seen that the disclosure contemplates the presentation ofnumerous and various means for sensing the position of a specific pusherassociated with a specific track system located in conjunction with aspecific shelf within a retail establishment. This data, for all suchpusher and track systems within the establishment is acquired and passedto a transmitter 70, for radio frequency transmission to a receiver 24,which then passes it through a router 28 to a user device 32. This datais acquired routinely and sequentially, at a rapid duty cycle, such thatinstantaneous information regarding the status of all products withinthe retail establishment can be monitored and obtained. Any rapidchanges in product at a particular location, signaling theft, accidentor the like, can be immediately monitored and an appropriate alarm orremedial action commenced. Inventory control is greatly facilitated andassurance that an out of stock situation is not experienced is possible,by relaying instructions to the PDA 44.

FIG. 23 illustrates another embodiment of the shelf system, comprising aplurality of track units 60 that receive product and are disposedbetween a back rail 62 and a front rail 64. The track units 60 areoriented normal to the rails 62, 64, and comprise a pusher 66 that urgesproduct toward the front rail 64, such that when a consumer removes aproduct unit, remaining product units in the track 60 are pushed forwardin an orderly fashion and retained between the pusher 66 and the frontrail 64. The pusher 66 moves between the back rail 62 and the front rail64 along a pair of tracks 68.

The system further comprises a wireless transceiver 70 that receivesinformation from, and transmits information to, each track unit 60. Forinstance, the transceiver 70 can receive information related to pusherposition at predetermined temporal intervals.

Each track unit additionally includes a back clip housing or cover 330that covers a back clip housing and other components described in moredetail with regard to FIG. 24.

FIG. 24 is a cross-sectional view of the back clip housing 330 andassociated components. A pusher track 68 and potentiometer 92 a arecoupled to a back clip housing 332 with a PCB 102 that is covered by theback clip cover 330. The cover 330 covers a portion of the back rail 62that includes a plurality of spring connectors 104 and associated copperconductive strips 162. The clip cover 330 provides additional protectionfor the track unit circuitry to reduce damage caused by spills, dust ordirt, tampering, etc.

FIG. 25 illustrates another embodiment of the shelf system with a backclip cover 330 a that covers several components of the system. Thesystem comprises a plurality of track units that receive product and aredisposed between a back rail 62 and a front rail 64. The track units 60are oriented normal to the rails 62, 64, and comprise a pusher 66 thaturges product toward the front rail 64, such that when a consumerremoves a product unit, remaining product units in the track 60 arepushed forward and retained between the pusher 66 and the front rail 64,and on at least one side by a divider 132. The pusher 66 moves betweenthe back rail 62 and the front rail 64 along one or more tracks 68. Eachtrack unit additionally includes a back clip housing or cover 330 a thatcovers a back clip housing and other components described in more detailwith regard to FIG. 26.

FIG. 26 is a cross-sectional view of the back clip housing 330 a andassociated components. A pusher track 68 and potentiometer 92 a arecoupled to a pusher paddle 66 and to a back clip 100 with a PCB 102 thatis covered by the back clip cover 330 a. The cover 330 a covers aportion of the back rail 62 that includes a plurality of springconnectors and associated copper conductive strips 162. The clip cover330 a provides additional protection for the track unit circuitry toreduce damage caused by spills, dust or dirt, tampering, etc. The systemalso includes an actuator or contact pad 350 that exerts a force on thepotentiometer 92 a to indicate the location of the pusher paddle 66 onthe track 68. In this embodiment, the coil spring that urges the pusherpaddle towards the front of the track 68 is not shown.

Thus it can be seen that the various aspects of the disclosure have beensatisfied by the structure and methodology presented above. While inaccordance with the patent statues only the best known and preferredembodiments of the disclosure have been presented and described indetail, the disclosure is not limited thereto or thereby. Accordingly,for an appreciation of the true scope and breadth of the subjectdisclosure, reference should be made to the following claims and theequivalents thereof.

1. An inventory shelf monitoring system, comprising: at least one tracksystem mounted on an associated shelf, the track system including atrack receiving a pusher that is biased toward a front end of the track;a sensor fixed in relation to the track; an actuator attached to thepusher and in communication with the sensor, the sensor emitting a firstoutput signal corresponding to an instantaneous location of the pusherin relation to the track; a microprocessor coupled to the sensor,wherein the microprocessor controls power to the sensor and measurespusher position; an electric bus located adjacent a rear end of thetrack, wherein the microprocessor is coupled to the electric bus; a dataacquisition and transmitter circuit associated with the associated shelfand in data receiving communication with the sensors of the track systemby receipt of the first output signals, the acquisition and transmittercircuit emitting a second output signal corresponding to the identityand location of the pusher of the at least one track system located onthe associated shelf as a function of measured pusher position; and areceiver receiving the second output signals.
 2. The inventory shelfmonitoring system according to claim 1, wherein the track system has awiper contact in contacting engagement with the bus.
 3. The inventoryshelf monitoring system according to claim 2, wherein a plurality ofbuses is provided, including a ground bus, a signal bus, and a voltagesupply bus.
 4. The inventory shelf monitoring system according to claim3, wherein the microprocessor comprises: a first port coupled to apotentiometer signal wiper; a second port coupled to the ground bus andto an anode of a capacitor; a third port coupled to a potentiometerground wiper; a fourth port coupled to the signal bus; a fifth portcoupled to a cathode of the capacitor; and a sixth port coupled to thesignal bus and to the fourth port; and wherein the voltage supply bus iscoupled to a potentiometer voltage wiper to provide a voltage thereto.5. The inventory shelf monitoring system according to claim 4, whereinthe plurality of buses is interconnected between the data acquisitionand transmitter circuit of the associated shelf and the microprocessorof the sensor circuit of each of the track systems located on theassociated shelf.
 6. The inventory shelf monitoring system according toclaim 1, wherein the electric bus is mounted to a housing such that itis oriented vertically.
 7. The inventory shelf monitoring systemaccording to claim 1, wherein the sensor comprises a potentiometer andthe actuator comprises a contact member on the pusher, the contactmember defining the signal wiper of the potentiometer.
 8. The inventoryshelf monitoring system according to claim 1, wherein the actuatorcomprises a rotary wheel operatively connected to the pusher andemitting a signal to the sensor corresponding to rotational activity ofthe wheel, wherein the wheel is at least one of an encoded wheel andpiezoelectric pulse generator.
 9. The inventory shelf monitoring systemaccording to claim 1, wherein the sensor comprises an ultrasonictransponder, sending and receiving ultrasonic waves, the actuatorcomprising a reflector attached to the pusher reflecting the ultrasonicwaves from the transponder back to the transponder.
 10. The inventoryshelf monitoring system according to claim 1, wherein the sensorcomprises a light transponder having a light emitter and an array oflight receivers, and the actuator comprises a reflector attached to thepusher reflecting light from the emitter back to the array of lightreceivers.
 11. The inventory shelf monitoring system according to claim1, wherein the actuator comprises a signal strength monitor, monitoringthe strength of a signal taken from the group of optical, magnetic,radio frequency and acoustic signals, the signal strength beingindicative of a position of the pusher.
 12. The inventory shelfmonitoring system according to claim 1, wherein the sensor comprises aradio transponder having a radar sender and receiver, and the actuatorcomprises a reflector attached to the pusher reflecting radar signalsreceived from the sender to the receiver.
 13. The inventory shelfmonitoring system of claim 1, further comprising a central processingunit in communication with the receiver.
 14. A product inventorymonitoring system, comprising: a front rail; a back rail spaced from thefront rail; a plurality of track units coupled to the front rail and theback rail to form a modular system, each track unit comprising: aspring-loaded pusher that applies force to one or more associatedproduct packages to urge the one or more associated packages toward thefront rail; a contact pad mounted on a bottom face of the pusher incontact with a sensor strip mounted to the track, the sensor strip beingelectrically coupled to a microprocessor in a sensor circuit, whereinthe microprocessor is in turn coupled to a plurality of buses mounted toone of the front rail and the back rail; a power source that supplies avoltage to the one of the front rail and the back rail; and a dataacquisition and transmitter circuit that is coupled to the track unitand determines a position of the pusher as a function of a voltagedifference between the power supply and a voltage detected across thesensor strip; and a user device that receives pusher positioninformation and generates a report comprising information related toproduct package count in each of the plurality of track units.
 15. Thesystem according to claim 14, wherein the sensor strip includes a sliderpotentiometer.
 16. The system according to claim 14, wherein theplurality of buses includes a ground bus, a signal bus, and a voltagesupply bus.
 17. The system according to claim 14, wherein themicroprocessor comprises: a first port coupled to a potentiometer signalwiper; a second port coupled to the ground bus and to an anode of acapacitor; a third port coupled to a potentiometer ground wiper; afourth port coupled to the signal bus; a fifth port coupled to a cathodeof the capacitor; and a sixth port coupled to the signal bus and to thefourth port; and wherein the voltage supply bus is coupled to apotentiometer voltage wiper to provide a voltage thereto.
 18. A systemthat facilitates monitoring inventory, comprising: a data acquisitionand transmitter circuit that is interconnected to each of a power bus, aground bus, and a signal bus, wherein the data acquisition andtransmitter circuit comprises: a dedicated microprocessor chip thatreceives the data input signals from the data bus, from each of aplurality of track units associated with the data acquisition andtransmitter circuit; and wherein the microprocessor formats datareceived from the plurality of track units for transmission, and passesa formatted output signal through transmitter circuitry for emission asan RF signal from an antenna; and a receiver that receives thetransmitted output signal and forwards the transmitted output signalthrough a router to a user device that generates at least one of aninventory report and a pilferage report; wherein each track unitincludes a pull-up resistor.
 19. The system according to claim 18,further comprising a sensor circuit coupled to each track unit, whereinthe sensor circuit provides information to the data acquisition andtransmitter circuit including a serial number or location of the trackunit and a specific location of a pusher associated therewith.
 20. Thesystem according to claim 18, wherein the microprocessor chip formatsthe data received from the plurality of track units to include one ormore of shelf identity information for an associated shelf on which theplurality of track units is disposed, identity information for eachtrack unit and its dedicated pusher, status of a battery supplying powerto the data acquisition and transmitting circuit and the sensor circuit,and a messaging sequence number that prevents duplication of data.